All times, unless otherwise noted, are UT (subtract four hours and, when appropriate, one calendar day for EDT)

10/1 Mercury is 1.8 degrees north of the first-magnitude star Spica (Alpha Virginis) at 1:0010/3 Venus is 0.1 degree south of the first-magnitude star Regulus (Alpha Leonis) at 8:0010/4 Jupiter is stationary at 14:0010/5 The Moon is at apogee, subtending 30 arc minutes from a distance of 405,160 kilometers (251,755 miles), at 1:00; Jupiter is 0.9 degree north of the Moon, with an occultation taking place in southern Australia, at 21:0010/6 Mercury is 3 degrees south of Saturn at 7:0010/7 Asteroid 1 Ceres is 0.9 degree north of the Moon, with an occultation taking place in southern Africa, at 21:0010/8 Mercury is at aphelion today; the peak of the Draconid meteor shower (10 to 30 per hour) occurs at 2:00; Last Quarter Moon occurs at 7:33 10/9 The Curtiss Cross, an X-shaped illumination effect located between the craters Parry and Gambart, is predicted to occur at 1:18 10/12 Venus is 6 degrees north of the Moon at 19:00 10/15 The new moon (lunation 1111) occurs at 12:0210/17 The Moon is at perigee, subtending 33 arc minutes from a distance of 360,672 kilometers (224,111 miles), at 1:00; Mercury is 1.3 degrees south of the Moon at 2:0010/18 Mars is 2 degrees south of the Moon at 13:0010/20 Mars is 4 degrees north of first-magnitude star Antares (Alpha Scorpii) at 6:0010/21 The peak of the Orionid meteor shower (10 to 20 per hour) occurs at 4:00; asteroid 4 Vesta is stationary at 7:00 10/22 First Quarter Moon occurs at 3:32; the Lunar X, also known as the Purbach or Werner Cross, an X-shaped illumination effect involving various rims and ridges between the craters La Caille, Blanchinus, and Purbach, is predicted to occur at 11:0110/24 Neptune is 6 degrees south of the Moon at 16:0010/25 Saturn is in conjunction with the Sun at 8:0010/26 Mercury is at greatest eastern elongation (24 degrees) at 22:0010/27 Uranus is 5 degrees south of the Moon at 10:00 10/28 Mercury is at its greatest heliocentric latitude south today10/29 Full Moon, known as the Blood Moon and this year’s Hunter’s Moon, occurs at 19:4910/31 Venus is at aphelion; asteroid 1 Ceres is stationary at 21:00

Ejnar Hertzsprung and Henry Norris Russell were born this month.

Giovanni Cassini discovered Saturn’s odd satellite Iapetus on October 25, 1671. Two of the satellites of Uranus, Ariel and Umbriel, were discovered by William Lassell on October 24, 1851. Lassell discovered Triton, Neptune’s brightest satellite, on October 10, 1846.

The Draconid (formerly the Giacobinid) meteor shower peaks on the evening of October 8. The Orionid meteor shower peaks during the morning of October 21. The waxing crescent Moon sets as Orion rises in the east so conditions will be excellent. Orionid meteors are fragments of Comet 1P/Halley. A Taurid fireball swarm is a possibility from October 28 to November 11. Unfortunately, the Moon is full on October 29.

During the second half of the month, the zodiacal light may be visible in the pre-dawn eastern sky from a dark site.

The Moon is 14.9 days old and is located in Pisces on October 1 at 0:00 UT. The Moon reaches its greatest northern declination on October 6 (+21.0 degrees) and its greatest southern declination on October 19 (-21.0 degrees). Longitudinal libration is at a maximum of +6.8 degrees on October 24 and a minimum of -6.7 degrees on October 11. Latitudinal libration is at a maximum of +6.8 degrees on October 11 and a minimum of -6.8 degrees on October 24. Large tides will occur from October 15 through October 18. Visit http://saberdoesthes...does-the-stars/ for tips on spotting extreme crescent Moons and http://www.curtrenz.com/moon06.html for Full Moon data. Times and dates for the lunar light rays predicted to occur in October are available at http://www.lunar-occ...o/rays/rays.htm

The Sun is located in Virgo on October 1 at 0:00 UT. The first recorded solar eclipse took place on October 22, 2136 B.C.

During October evenings, Mercury and Mars are in the southwest, Saturn is in the west, Uranus is in the east, and Neptune is in the southeast. At midnight, Jupiter is located in the east, Uranus in the south, and Neptune in the southwest. Venus can be found in the east and Jupiter is in the southwest in the morning sky.

At midmonth, Mercury can be seen during evening twilight, Venus rises at 4:00 a.m. local time, Mars sets at 8:00 p.m. local time, Jupiter rises at 9:00 p.m. local time and crosses the meridian at 4:00 a.m. local time, and Saturn sets at 7:00 p.m. local time for observers at latitude 40 degrees north.

The finest evening apparition of Mercury for southern hemisphere observers takes place this month. Mercury passes 1.8 degrees north of Spica on October 1, three degrees south of Saturn on October 6, and close to the Moon on the evening of October 16. The speediest planet is at aphelion on October 8 and greatest eastern elongation on October 26.

Venus passes a mere seven arc minutes south of Regulus on October 3, the closest approach of a planet to a first-magnitude star this year, and six degrees north of the waning crescent Moon on October 6. It is within 2.5 degrees of Regulus from October 1 to October 5 and five degrees of Regulus through October 7. As the month progresses, Venus climbs higher into the sky. Northern hemisphere observers have a more favorable view due to the angle of the ecliptic. By the end of October, Venus rises three hours before the Sun. The most brilliant planet drops slightly in magnitude (-4.1 to -4.0) and apparent size (16 to 13 arc seconds) but grows more gibbous (71 to 80% illuminated) during the course of the month.

Mars travels eastward from Libra into Scorpius on October 6 and into Ophiuchus after the middle of October. Observers in the southern hemisphere are favored. Mars passes between Delta and Beta Scorpii on the nights of October 11 and October 12. The Red Planet lies 3.5 degrees north of the slightly brighter Antares, the “rival of Ares”, on October 20.

Uranus spends October retrograding through Pisces. It culminates at midnight. Uranus is located 0.3 degree west-southwest of the sixth-magnitude star 44 Piscium on October 1. By the end of October, the westward motion of the planet increases the separation to 1.5 degrees.

As Neptune retrogrades through Aquarius this month, it is located less than 0.5 degree south of the fifth-magnitude star 38 Capricorni.

Pluto is located in northern Sagittarius near the open cluster M25. The dwarf planet is visible shortly after nightfall. Detailed finder charts are available on pages 52 and 53 of the June issue of Sky & Telescope and on page 236 of the RASC Observer’s Handbook 2012.

Asteroid 1 Ceres (magnitude 8.5) travels eastward through northeastern Orion and southwestern Gemini this month. It’s occulted by the Moon on October 7 and is stationary on October 31. Asteroid 4 Vesta (magnitude 7.8) heads eastward through Taurus before retrograding. It is stationary on October 21. A finder chart for the two minor planets appears on page 51 of the October issue of Sky & Telescope. During October, asteroid 2 Pallas glides southwestward through western Cetus. Pallas (magnitude 8.3) lies about one degree south-southwest of Iota Ceti (magnitude 3.5) on October 1. The faint asteroids 371 Bohemia, 521 Brixia, and 35 Leukothea occult stars on the morning of October 13, late on the night of October 21, and the evening of October 31 respectively (see page 52 of the October issue of Sky & Telescope). For information on this year’s bright asteroids and upcoming asteroid occultation events respectively, consult http://www.curtrenz.com/asteroids and http://asteroidoccultation.com/

Comet C/2011 F1 (LINEAR) takes a southeastern course through Serpens Caput this month. On October 1, the tenth-magnitude comet is 0.4 degree northeast of the fifth-magnitude star 3 Serpentis. Comet F1 LINEAR lies within two degrees of the bright globular cluster M5 (magnitude 5.7) from October 4 to October 8.